Grey-shanked douc (Pygathrix cinerea)

Also known as: Gray-shanked douc langur, Grey-shanked douc langur
Synonyms: Pygathrix nemaeus cinerea
KingdomAnimalia
PhylumChordata
ClassMammalia
OrderPrimates
FamilyCercopithecidae
GenusPygathrix (1)

The grey-shanked douc is classified as Critically Endangered (CR) on the IUCN Red List (1) and listed on Appendix I of CITES (2).

An extremely rare primate found only in the Central Highlands of Vietnam, the grey-shanked douc (Pygathrix cinerea) is one of the world’s 25 Most Endangered Primates (3). Like other doucs, this species is among the most strikingly coloured of all primates, with almond-shaped eyes and a white mouth surrounded by yellow-orange to light brown facial skin, and a band of white stretching around the sides of the head to the ears (4). A broad black bar stretches across the forehead and white whiskers, as long as 12 centimetres, protrude conspicuously from the sides of the head (4). The different species of douc may be distinguished by the colour of their shanks, and the grey-shanked douc can be identified by its dappled, dark grey legs, as well as by its light grey crown, back and arms, and white tail, which is almost as long as the rest of the body and ends in a thin tassel (4) (5). The belly is light grey to almost white, the fingers and feet are black, and the throat is white with an orange ring around the neck (5).  

Described as recently as 1997, the grey-shanked douc was initially considered a subspecies of the red-shanked douc (Pygathrix nemaeus). However, recent genetic studies provided convincing evidence that it is indeed a separate species (6).  

The grey-shanked douc is only known from the provinces of Quang Nam, Quang Ngai, Binh Dinh, Kon Tum, and Gia Lai in the Central Highlands of Vietnam, where the population is highly fragmented and threatened by further habitat loss. The full extent of the species’ distribution is unclear; however, photographs of hunted animals from south-east Laos and north-east Cambodia suggest that the grey-shanked douc may also occur in these neighbouring countries (1) (3). 

The grey-shanked douc inhabits both primary and disturbed evergreen and semi-evergreen rainforests (1).

Never seen on the ground in the wild, the grey-shanked douc spends almost all of its time feeding high in the treetops. While traversing the canopy, it moves with a distinctive gait on all four limbs and swings between the branches using its elongated arms (4). It prefers to eat young, tender leaves, which may comprise as much as three quarters of its diet, but it will also eat plant buds, fruits, seeds and flowers (1). As this largely leafy diet is of low nutritional value, the grey-shanked douc’s stomach can hold large volumes, and the stomach contents may weigh as much as a quarter of an adult’s body weight (7). At night, the grey-shanked douc sleeps in carefully selected large trees with a thick canopy (5). 

Travelling in groups, the size of which varies with habitat quality, the grey-shanked douc is a very social primate, and will readily play and groom together. Motherhood is a shared duty within the group, giving mothers time to feed, as well as helping to integrate the young into the group. Social bonds within these douc groups are vitally important and communication takes place through a wide variety of vocal and visual signals, as well as through tactile communication in the form of social grooming. Most groups are multi-male and multi-female, with more females than males, and there is a marked dominance hierarchy, with all males dominant over the females. Breeding activity is likely to peak between February and June, when there is an abundance of seasonal fruits, and a single infant is born after an estimated gestation period of around 210 days. Females reach maturity at around five years of age, and probably breed every two years (4).

Having declined over recent decades by around 80 percent, surveys in 2004 suggest that perhaps as few as 550 to 700 grey-shanked doucs remain in the wild, and that with little sign of the threats to the species’ decreasing, its population is continuing to fall (1) (4) (8). The main threat to this species is hunting for food and for use in traditional ‘medicines’ (1). It is also captured in snares for the pet trade, although captive animals rarely survive long due to their highly sensitive digestive system (1) (4). At Kon Cha Rang Nature Reserve, which contains one of the largest remaining grey-shanked douc populations, there is a traditional hunting season in September, with large numbers of snares set in trees to catch this monkey (8). The grey-shanked douc is also particularly vulnerable to hunting with guns, as in response to disturbance it typically remains motionless in the canopy rather than fleeing (1). This exploitation is compounded by the loss of the grey-shanked douc’s forest habitat which is highly fragmented and degraded, and continues to be lost to logging and agriculture at a rate of around 100 square kilometres per year (1). Many communities surrounding these forests employ shifting agricultural strategies, with a tendency to convert forest farming and livestock grazing areas, greatly increasing the pressure on this rare monkey’s habitat (8).  

Supporting at least 24 species of primate, a quarter of which are thought to be endemic, the protection of Vietnam’s natural habitats is of critical importance to primate conservation (4). However, conservation efforts in Vietnam are far too often hindered by the weakness of the country’s protective legislation and law enforcement, allowing hunting and habitat loss to continue to threatened many rare species. This is further compounded by the dependency of many people upon natural resources and the small amount of funds allocated to conservation work (9). 

The grey-shanked douc is afforded the highest level of protection under the Wildlife Protection Law in Vietnam, and also occurs in several nature reserves, although law enforcement in these areas is variable and often inadequate, with hunting of the species continuing to be prevalent (1) (4). Recognising the vulnerability of the grey-shanked douc to extinction, the Frankfurt Zoological Society has undertaken several studies on the species in the wild, to provide recommendations for the establishment of special ‘Species Protection Areas’, which aim to increase connectivity between the currently-isolated populations (3). There is also an ongoing captive-breeding program for this species at the Endangered Primate Rescue Center at Cuc Phuong National Park (1) (10).

To find out more about the grey-shanked douc langur and its conservation, see:

For more information on primates in Vietnam, see:

Authenticated (20/11/10) by Matthew Richardson, primatologist and author.

  1. IUCN Red List (August, 2010)
    http://www.iucnredlist.org/
  2. CITES (August, 2010)
    http://www.cites.org/
  3. Mittermeier, R.A. et al. (2009) Primates in Peril: The World’s 25 Most Endangered Primates 2008-2010. IUCN/SSC Primate Specialist Group, International Primatological Society, and Conservation International, Arlington, VA. Available at:
    http://data.iucn.org/dbtw-wpd/edocs/2009-067.pdf
  4. Nadler, T., Momberg, F., Dang, N.X. and Lormee, N. (2003) Leaf Monkeys: Vietnam Primate Conservation Status Review 2002 – Part 2. Fauna and Flora International Vietnam Program and Frankfurt Zoological Society, Hanoi, Vietnam.
  5. Primate Info Net – Douc langur (August, 2010)
    http://pin.primate.wisc.edu/factsheets/entry/douc_langur/ref
  6. Roos, C., Thanh, V.T., Walter, L. and Nadler, T. (2007) Molecular systematics of Indochinese primates. Vietnamese Journal of Primatology, 1: 41-53.
  7. Macdonald, D.W. (2006) The Encyclopedia of Mammals. Oxford University Press, Oxford.
  8. Long, H.T. (2007) Distribution, population and conservation status of the grey-shanked douc (Pygathrix cinerea) in Gia Lai Province, Central Highlands of Vietnam. Vietnamese Journal of Primatology, 1: 55-60.
  9. Lippold, L.K. and Thanh, V.T. (1998) Primate conservation in Vietnam. In: Jablonski, N.G. (Ed.) The Natural History of the Doucs and Snub-nosed Monkeys. World Scientific Publishing, Singapore.
  10. The Endangered Primate Rescue Centre (August, 2010)
    http://www.primatecenter.org/